This invention relates generally to a "pan" for a ceiling mounted light fixture and more particularly, to such a "pan" which limits the transfer of heat generated by the electric lamps of the light fixture to the ceiling support surface.
Conventionally, light fixtures which are mountable on ceilings or other flat support surfaces, include what is called in the lighting industry, a "pan" to provide support to the fixture and through which the electrical wiring connecting the lamp socket(s) of the fixture to an electrical junction box, pass. The "pan" is most commonly a relatively flat member which attaches along one surface thereof by screw fasteners or the like to the threaded tabs of an electrical junction box mounted in the ceiling and which also supports the lamp sockets of the fixture on the opposite surface thereof. A decorative glass or plastic shade or refractor is joined to the "pan" and extends downwardly therefrom in covering relation to the lamp sockets.
It has been determined that "pans" of the type described permit too great heat transfer from the lighted lamps of the fixture back to the ceiling support, even in the case where a layer of insulation is provided between the "pan" and ceiling. If the heat transferred to the ceiling becomes excessive, it is possible that the ceiling surface will be damaged or discolored. It is also possible that the lamp fixture could become a fire hazard.
In order to reduce the heat transferred to a ceiling support from a light fixture mounted thereon, light fixture "pans" have been designed which include separate sections which are joined together but in spaced relation. One of the sections is secured to the ceiling while the other section is suspended from the first-mentioned section and accommodates the lamp sockets of the fixture. An air space between the section helps to dissipate heat produced by the lighted lamps. Examples of such light fixtures are illustrated in U.S. Pat. Nos. 3,141,086 and 4,044,246.
Still other types of light fixture "pans" which employ air passages to dissipate heat produced in the fixture are known in the art. Such fixtures are shown, for example, in U.S. Pat. Nos. 2,512,948 and 3,189,740.
While the above described light fixtures do aid in the reduction of heat transferred from the lighted lamps to the fixture to the ceiling surface, the "pans" of the first discussed group of patents rely on heat dissipation by air circulation, the efficiency of which tends to be limited and the "pans" of the second group of patents are merely variations of the standard "pan" discussed initially and as such are not as effective in dissipating heat as is desired.